/*let intervalID = setInterval(myCallback, 1000);

function myCallback() {
    console.log(Date.now());
}*/

let intervalID;

function startChange() {
    if (!intervalID) {
    intervalID = setInterval(changeRandomColor, 1000);
    }
}

function stopChange() {
    clearInterval(intervalID);
}

/*function changeColor() {
    if (document.body.style.backgroundColor !== "blue") {
        document.body.style.backgroundColor = "blue";
        document.body.style.color = "white";
    } else {
        document.body.style.backgroundColor = "white";
        document.body.style.color = "blue";
    }
}*/

function changeRandomColor() {
    const randomColor = Math.floor(Math.random() * 16777215).
    toString(16);
    document.body.style.backgroundColor = `#${randomColor}`;
    }
    
document.getElementById("start").addEventListener("click", startChange);
document.getElementById("stop").addEventListener("click", stopChange);

